A typical router receives an Internet Protocol (IP) packet, uses a router table to look up a port corresponding to a router interface, and immediately forwards the IP packet to that router interface. In a network having a fixed infrastructure, the router interface sends the IP packet along a persistent communication link to a network destination.
Not all networks have a fixed infrastructure. A wireless ad-hoc network is a computer network in which the communication links are wireless and dynamic. The network is ad hoc because the nodes dynamically join and leave the network, and so the determination of which nodes forward data is made dynamically based on network connectivity. Types of wireless ad-hoc networks include Mobile ad hoc networks (MANets) and wireless mesh networks.